Bedding foundations or so-called box spring assemblies comprise a base, usually made of wood, an upper grid including a generally rectangular border wire and a plurality of spring modules sandwiched between and secured to the upper grid and base. Such box spring assemblies or bedding foundations are bulky for purposes of shipping to a bedding manufacturer and costly in terms of storage space. When such a bedding foundation is shipped to a bedding manufacturer, the space and shipping costs are increased and ultimately passed on to the customer.
In order to reduce the space requirements for purposes of shipping, it is customary to compress the bedding foundations to reduce their individual thicknesses and when compressed, to tie them in their compressed state. This involves providing presses and ties which are expensive to acquire and maintain. Additionally, the step of compressing and tying the compressed foundations adds extra time to the shipping process. At the delivery end, the bedding manufacturer must cut the tensioned ties and separate the individual foundation units before applying the requisite padding and covering. Due to the high tension of the ties, this process may be dangerous and requires great care on the part of the bedding manufacturer.
Bedding foundation assemblies are known which may be stacked prior to shipping and shipped as stacks of individual components. Shipping in this manner eliminates the need to compress a plurality of partially assembled bedding foundations for shipping purposes. Applicant's U.S. Pat. Nos. 5,052,064 and 5,361,434, each of which is fully incorporated by reference herein, disclose bedding foundations which may be shipped to a bedding manufacturer in this stacked manner. Multiple spring modules are commonly welded or otherwise secured to an upper grid which may be nestably stacked upon other similar subassemblies for shipping and/or storage purposes. Likewise, the wooden bases may be stacked for shipping and/or storage purposes. Upon arrival at the manufacturing facility, the bedding manufacturer removes the stacked components and assembles them as required to construct a bedding foundation before application of padding and covering. Oftentimes the upper grid and support wires are welded or otherwise secured together to create a spring assembly which may be unstacked and stapled or otherwise secured to a wooden base.
One difficulty bedding manufacturers encounter when constructing a bedding foundation like the one shown in applicant's U.S. Pat. No. 5,052,064 is that an operator must staple each valley of each generally corrugatedly-shaped support wire to the wooden base. This stapling process takes a great deal of time and is therefore, expensive. If performed manually, this process is subject to human error because the operator must properly align each support wire and be sure to staple each valley of each support wire to one of the rails of the wooden base. If automated, this process is subject to error because the stapling machine may fail to detect each valley of each support wire and consequently fail to staple each valley of each support wire to one of the rails of the wooden base.
Another difficulty bedding manufacturers encounter when constructing a bedding foundation like the one shown in applicant's U.S. Pat. No. 5,052,064 is that oftentimes some of the corrugatedly-shaped support wires are bent or otherwise deformed during shipment. Consequently, when the support wires of the spring assembly are stapled to a wooden base, the support wires may be incorrectly positioned relative to the wooden base. The result is a bedding foundation in which one or more of the corrugatedly-shaped support wires are stapled to the base in the wrong locations or missed partially or entirely by the stapler.
Therefore, there is a need for a stapling device which automatically staples the valleys of corrugatedly-shaped support wires to a wooden base in their correct locations. There is further a need for a method of stapling corrugatedly-shaped support wires to a wooden base in the correct positions, even if the support wires are bent.